Electric windshield wiper



Dec.y y172, 1944. G. E. coxoN ET A1.

ELECTRIC WINDSHIELD WIPER Filed Feb. 9, 1940 4 Sheets-Sheet l WW N @gaysDeu 12, 1944- G. E. coxoN ET A1. 2,364,603

ELECTRIC WINDSHIELD WIPER Filed Feb. 9, 1940 4 Sheets-Sheet 2 Dem 12,s1944. C; E COXQN ET AL 2,364,603

` ELECTRIC wINDsHILD WIPER Filed Feb. 9, 1940 4 Sheets-Sheet 3 Dec. 12,1944. E COXON ET AL 2,364,603

ELECTRIC WINDSHIELD WIPER Filed Feb. 9, 1940 4 Sheets-She-ai'Il 4 f@ f5@f1-@ 103 100 JZQ Patented Dec. l2, 1944 ELEQ'ERIC SHIELD EB George E.Coxon, Cicero, and Willard E. Farr,

Chi

cago, lll., assignors to Stewart-Warner Cor poration, Chicago, lll., acorporation ol'v Vir sinia `-Application February 9, 1940, Serial No.31S,13

(Cl. 15u-253) l? Claims.

The present invention relates to windshield wipers and has for itsprimary object the pro vision of a new and improved electricallyactuated windshield wipen An object of the present invention is theprovision of an electric motor actuated windshield wiper that isreliable in operation and which may be economically and simplymanufactured and installed.

A further object of the present invention is the provision of a new andimproved electric motor actuated windshield wiper so constructed andarranged that the wiper blade, or blades, are always parked in the sameposition when the wiper is turned oil.

Another object of the present invention is the provision of a Wiper ofthe type described, which is stopped substantially immediately when theelectric motor is disconnected from the source of power. I

Another object of the invention is the provision of a compact,economically manufactured,

Fig. 1 is a partial vertical cross-sectional view 3@ through anautomotive vehicle showing the apparatus of the present inventioninstalled in the vehicle:

F18. 2 is a partial top plan view, on a somewhat larger scale, of theapparatus shown in Fig. i;

' 3 is a partial front elevation ot the control mechanism shown in thepreceding'figures;

Fig. 4 is a horizontal cross-sectional view, on an nlarged scale,` takenalong the line 6 5 of Fig.A i

Fig. 5 is a. vertical cross-sectional view, taken along the line 5 5 ofFig. i;

Fig. 6 is a vertical cross-sectional view,` taken along the line ofFig.- 5;

Fig. 9 is a vertical sectional'view, taken along 'the une s-.-s. of Fig.s; and

Fig. A10 is a. schematic diagram of the electrithe windshield l2. Theyare oscillated by an electric motor l supported upon a transversebracket t6. The motor is operatively connected to the blades through apair of oppositely extending connecting rods 88,'connected 'at theiradjacent ends to a crank pin 2@ rotated by the motor through reductiongears contained in a casing 22, and at their opposite ends to crank armstft (only one of which is shown) connected in turn to the blades throughoscillatable pins inot shown) mounted upon and extending through thewindshield frame. Rotation of crank pin 2&3 by the motor impartsreciprocatory motion to the cranky arms t8, and these in turn oscillatethe blades through the oscillatable pins. 'fthe motor is controlled inpart by a switch on the dashboard ci the automobile and in part by thecontrol mechanism contained within a casing 2o, also supported by thebracket it, in a manner to be described shortly in connection with Fig.lo. The control mechanism comprises a switch intermittently opened andclosed by motor lli through a depressor arm 21E; actuating a switchoperating fbutton 3o, which depressor arm carries the previouslymentioned pin 2li. in Fig. i the depressor arm and the button are shownin the positions occupied thereby when the switch, hereinafter to hereferred to as a cam switch, is open.

The control mechanism is so constructed and arranged mechanically andelectrically with re sp'ect to the dash switch that upon actuation ofthe dash switch the motor isv immediately ener gized to operate thewiper blades. 'When the switch is actuated to out 0E the supply of powerto the motonthe motor is supplied with power through the cam switchuntil the wiper blades reach a certain position, whereupon the motorarmature is connected to ground while the motor held remains energizeddynamically to brake and quickly stop the motor with the blades in theirproper parking position.

` Referring now to Fig. l0, the control mechanism casing 26 maybe seento include the apparatus and connections schematically indicated withinthe dotted lines-al1 this being contained within or mounted upon thecontrol` mechanism casing. The motor field and armature are indicated byreference-characters 3| and 36 and the cal connections embodied in the'apparatus' of 50 .dash switch by reference character 38. Power y issupplied to the terminals lll and 42, the latter the present invention.v

Referring now to the figures, and more 'particularly to Figs. 1 and2, itmay be seen that the conventional wiper blades Il (only one of Vbeingthe ground terminaland the former being connected through a line fuse 44to a terminal AI6. .The dash switch I8 is connected to terminal which isshown) are mmm m as to .engage 65 I6 and another terminal 4I. throughconductors 50 and 52, respectively. The cam switch 54 is connected tothe same terminals, i. e., in parallel with switch 38, throughconductors 55, 56 and 51, so that when either switch is closed, relay 58is connectedto the power supply through the switch and conductors 51 and60. Connection of the relay across the power supply results in theenergization of the motorarmature and field; the former through theconductor 62, a relatively fixed spring contact arm 64, a movable springcontact arm 66, conductor 68, terminal 10, conductor 12, and groundconnection 14; and the latter through conductor 62, a relatively fixed yspring -contact arm 16, a movable bimetallic spring contact arm 18(which is compensated for changes in ambient temperature and the heatingeiTect of current flowing therethrough in a manner to be describedhereinafter), conductor 80, terminal 82, conductor 84, and groundconnection 86. The spring arm 18 is so connected that when heated itmoves upwardly.

In order to maintain the motor field 34 connected across the line toprovide dynamic braking after de-energization of the solenoid, thecontact arm 18 is surrounded by a heating coil 88 connected byconductors 90 and 92 to conductor 51 and ground, respectively. Duringdynamic braking, the armature circuit of the motor is closed throughconductors 12, 68, the movable contact arm 66, a relatively fixed springcontact arm 94, and return connections 92 and 14.

The movable contact arms 66 and 18 are operated by the solenoid throughan armature 96 carrying an insulated contact actuating arm 98.

To initiate operation of the windshield'wiper, assuming terminals 40 and42 to be connected to a source of power, such for instance as a batteryand by means of the ignition switch, it is necessary only to close thedash switch 38. The motor armature and field are energized in the mannerpreviously described through energization of relay 58, and the Wiperblades oscillated and cam switch intermittently opened and closed. Tostop the wiper, dash switch 38 is opened. If cam switch 54 happens to beopen, relay 58 is immediately de-energized, but if not,

. Figs. 4, 7 and 8).

The relay 58 is mounted on a generally rightangled supporting bracket|20 secured by a screw |22 to projection ||2, as best shown in Figs. 5,6 and '1. The relay armature 96 is apertured and loosely mounted on areduced end portion` |24 of bracket |20, where it is held in place by astop |26 clipped to the end portion. The contact actuating portion 98,made of insulating material, is riveted to the free end of the armature.The free end of portion 98 is stepped, as indicated by referencecharacters |28 and |30 (see Fig. 6), so that it may engage and operateboth contact arms 66 and 18, the end portions of which are at anangle tothe major portions so as to provide easier movement of the contact; armsby the relay, as well as the return of the armature to its normalposition. The armature is provided with a button-like projection |32, toprovide proper spacing between the armature and relay core |34 (seeFigs. 5 and 9), and undesired chattering is prevented by a spring |35peened on the side of bracket |20 and bearing against the edge ofarmature 96.

The fuse 44 is mounted on a fuse block |38 of insulating materialmounted by screws upon a further projection |38 formed integral with therelay supporting bracket |28 and upon a U- shaped support |40 riveted tobracket |88 (see The fuse is mounted on spaced apart clips |42 securedand separated from the block |36 by metallic spacers |44 and hollowrivets- |46, one of which has attached to it a terminal lug |48-the oneto which fuse terminal 46 is secured. The terminal screw 48 is alsomounted on the fuse block. A cork gasket |58 insures proper spacingbetween the fuse block the relay is de-energized when the wiper bladesare in a certain position. 'I'he de-energization of the relay connectsthe motor armature to ground and permits the disengagement of contactarms 16 and 18 as soon as the latter has cooled. This effects quickstopping of the motor by dynamic braking and proper parking of the wiperblades.

I The control mechanism of the present invention is rugged, economicalto manufacture, and may be readily assembled, as will be brought out inthe following description thereof, during the course of which referenceis had mainly to Figs. 3 to 9, inclusive.

'I'he casing 26 comprises a base |00 of insulating material and adetachable cover |02 attached by nuts to a pair of metallic posts |04and |06 secured to the base. The posts secure to the base -a metallicbracket |08 having right-angled pro- Jections ||0, ||2, ||4 and ||6, bymeans of which thecam switch 54, relay 58, bimetallic contact arm 18,and the contact arms 64, 66, 16 and 94, respectively, are attachedthereto. Post |04 also forms the ground terminal 42. The cover |02 isapertured to receive the cam switch actuating button 30, which isresilently biased toward the cover by a mounting spring I8, as bestshown in Fig. 5. l A

and the cover |02. The fuse terminals 40 and 48 are also secured to thespacers.

The cam switch 54 is made in the form of a resilient contact arm, and ithas associated with it a relatively xed resilient contact arm |52. (SeeFigs. 5, 6 and 7.) These contact arms are mounted upon and insulatedfrom the previously mentioned portion ||0 of the supporting bracket |08,as well as from each other, by three insulating spacers |54. 'I'hecontact arms, spacers, and an adjusting bracket |56 in engagement withcontact arm |52 are all secured to bracket portion ||0 by a plate |58and a pair of rivets |60. A contact arm positioning screw |62 is mountedupon the outer end of bracket |56.

Cam switch 54, which is actuated by button 30, is provided with aU-shaped bracket |64 engageable by the button whenever the latter isdepressed, whereby contact buttons mounted upon arms 54 and |52 areintermittently disengaged. To make arm 54 suiliciently resilient towithstand operation for a long period of time, it is made with anenlarged portion 66 and is provided with a U-shaped aperture |68, asbest shown in Fig. 7. a rectangular portion (not shown) being securedbetween a pair 0f the insulating spacers |54.

The bimetallic contact arm mounted upon bracket portion |4 iscompensated against movement as a result of ambient temperature andcurrent variations by making it substantially U-shaped in construction.The U-shaped construction is aiorded by the contact carrying and heatersurrounded portion 18 and a portion |18 parallel thereto, the two beinginterconnected by a transverse portion |12. Upon variations in ambientvtemperature or the ow of current through the contact arm, theinterconnected ends move and the free, contact carrying end of arm 18remains stationary. When the heater 88 is i it by rivets Zilli, whichenergized, the heat generated thereby effectively acts upon arm 18,thereby causing the latter to remain in contact with contact arm 16 whenthe relay is de-energized, as explained heretofore. Portion is securedto bracket portion ||4 by rivets |14 and a plate |16 grounded by therivets. Contact arm portion |12, however, is insulated by spacers |18.

Contact arm 16 associated with the bimetallic contact arm is mountedupon bracket portion H6 by a pair of rivets |80 and a plate i232, asbest shown in Figs. 4, 8 and 9, A pair of spacers @t3 insulate the armfrom ground. The position of the arms may be adjusted by screw 84mounted at one end of adjusting bracket |86 secured to the bracketadjacent the arm. y

Contact arms S4, 66 and 96 are likewise mounted upon bracket portionllt. These arms are sepa-I rated vfrom each other and from the bracketportion llt by three insulating spacers itt. Contact arms Eiland 96 maybe adjusted by adjustingscrews ist and |9ifmounted upon the ends ofadjusting brackets E96 and lilll engaging contact arms tl andlll,respectively. The various parts described are all secured to bracketportion serve also to ground contact arm td. f

The motor armature and field terminals lll and l2 are mounted on basetilt in spaced relationship to bracket itil.

The above described construction is compact Vand rugged so that itsproper operation will not be aected by the vibration or jolting of theautomobile. The various parts may be fabricated inexpensively andreadily assembled.

While only one embodiment o the invention has been illustrated anddescribed, it is to be understood that the invention is not limited tothe specific details of the embodiment disclosed except as limited bythe claims.

What we claim as new and desire to secure by Leters Patent of the UnitedStates is:

l. A' control for a windshield wiper mechanically operable by anelectric motor and a source of energy therefor, including incombination,

means operable from a circuit breaking to a circuit making position, arelay energizable thereby for connecting the motor to said source ofenergy, a cam switch operable bythe motor for maintaining the supply ofpower to the relay after the last-mentioned means has been returned toits circuit breaking position until said motor and wiper reachpredetermined positions,

and means operative upon deenergization oi said relay for braking saidterval.

2. A control for windshield wiping means operable by an electric motorhaving an armature and lield Winding adaptedto be energized from motorfor a time iny a source of energy. including in combination, a

manually operable control switch, a relay energizable by said controlswitch and comprising switch means normally closing a. circuit throughthe amature and operable to connect said armature and eld to said sourceof energy, a cam actuated switch operable by the motor for maintainingsaid relay energized after opening oi .said control switch until themotor and wiping means reach predetermined positions, and means formaintaining the field winding temporarily connected to the source ofenergy after de-energizaton of the relay.

3. A control for a windshield wiper blade operable by an electric motorhaving an armature and a field winding adapted to be energized from asource of energy, including in combination. a relay, a manually operableswitch for energizing said relay, a switch intermittently opened andclosed by the motor connected in parallel to the manually operableswitch, said relay having a winding in ser'les with the switches andcomprising normally open switch` means in circuit vwith the motorarmature and field and switch means normally closing a, circuit throughthe armature, whereby when said manually operswitch means remains closedtemporarily to v connect the field to the source of energy afterde-energization of the relay, whereby when the manually operable switchis opened energy is supplied to the relay and heater until the motor andwiper blade are in predetermined positions I and the motor isdynamically braked upon deenergisation oi' the relay.

il. a. control for a windshield wiper mechanically operable by anelectric motor having an armature and a field winding adapted to beenergized from a source of energy,including in combination, a relay, amanually operable switch for energiring said relay, a switchintermittently opened and closed by the motor connected in parallel tothe manually operable switch, said relay having a winding in series withthe switches, said relay also comprising normally open switch meansin'circuit with the motor armature and iielol and switch. means normallyclosing a circuit through the armature, whereby when said manuallyoperable switch is closed the relay is energized to open the circuitthrough the armature and the armature and leld winding are connected tothe source of energy to render the motor operative to drive the wiper,the switch means associated with the` motor leld comprislng a bimetalliccontact carrying member and a heater associated with said bimetallicmember connected in parallel with,V said relay winding, said bimetallicmember being so arranged that the switch means' remains closed toconnect the field to the source of energy attende-energize.- tion of therelay, whereby-when the manually operable switch is opened energy issupplied to the relay and heater until the motor and wiper blade are inpredeterminedpositions and the mo tor is dynamically braked upondeenergizationof the relay. v

5. i control for a Windshield wiper mechanically operable by anelectric'motorhaving an armature and a eld winding adapted to beenergized from a source of energy. including in combination a relay, amanually operable switch for energizing said relay, a switchintermittently opened and closed by the motor connected in parallel tothe manually operable switch, said relay having a winding in series withthe switches, said relay also comprising normally open swltch'means incircuit with the motor armature and field and switch meansnormallyclosing a circuit through the armature, whereby when saidmanually operable switch is closed the relay is energized to open thecircuit through the armature and the armature and field winding areconnected to the source of energy to render 'the motor operative todrive the wiper, the switch means associated with the motor fieldcomprising a contact, a bimetallic contact carrying member and a. heaterconnected in parallel with said relay Winding, said bimetallic memberbeing so arranged that the switch means remains closed temporarily toconnect the field to the source of energy after de-energization of therelay, whereby when the manually operable switch is opened energy issupplied to the relay and heater until the motor and wiper blade are inpredetermined vpositions and the motor is dynamically braked uponde-energization. of the relay, said bimetallic member being soconstructed and arranged that the positionof said contactissubstantially unaffected by temperature changes resulting from changesin ambient temperature and current ilow through said bimetallic member.

V6. A relay including, in combination, a coil, an armature operablethereby, a contact carrying arm operable by said armature from oneposition to another, said arm being made of bimetallic material, andmeans including a heating element surrounding said arm energizedsimultaneously with said coil for temporarily maintaining said arm inits said other position after de-energization of said coil.

7. A relay including, in combination, a coil, an armature operablethereby, a current conducting arm operable by said armature from oneposition to another, said arm being substantially U- shaped, meanssupporting the outer end of one leg of the U, and a contact carried bythe free end of the other, said arml being made of bimetallic materialso arranged that the free contact contact carried by the free end of theother, and

means including. a heating element surrounding the contact carrying legof said arm energized simultaneously with said coil for temporarilymaintaining said arm in said other position after l de-energization ofvsaid coil.

9. In combination, a bracket, a coil mounted thereon, said bracketlhaving a portion extending beyond the coil, an armature of substantiallyrectangular cross-section. loosely mounted on said portion for pivotalmovement in opposite directions, and resilient means attached to saidYbracket bearing against the edgeof said armature in the vicinity of itspivot'and biasing the armature in a, direction generally coaxial withrespect to its pivotal axis thereby uniformly to restrain pivotalmovement of the armature in opposite directions. l 10. In a switch, thecombination including movable resilient contact carrying arm, arelatively iixed contact arm substantially parallel to and spaced fromsaid movable arm, means supporting said arms, arelatively narrowU-shaped bracket secured -by one'leg to said movable arm transversely ofthe arm, the other leg being spaced from the relatively xed arm, anapertured closure for said switch, a leaf spring semesses' cured to theunder side of said closure. and means movably extending through saidaperture supported by said leaf spring adapted to engage said bracket.

11. A control mechanism, including in combl- `nation, a base ofinsulating material, a substantially centrally apertured metallicbracket secured to said base and having a plurality of projectionsextending away from said base, a relay coil mounted upon one of saidprojections, an armature associated with said coil, a pair of switchassemblies actuated by said armature, said assemblies being mounted uponprojections located on one side of the coil, one'of said assembliescomprising a pair of spaced apart relatively iixed contact arms and anintermediate movable contact arm actuatable by said armature fromengagement with one into engagement with the other of said iixed contactarms, and a'third relatively xed contact arm located adjacent theothers, and the second of said assemblies comprising a substantiallyU-shaped bimetallic contact arm, having a free leg actuatable by saidarmature into engagement with said third contact arm, said free legbeing surrounded by heating means.

12. A control mechanism, including in combination, a base, a bracketsecured to said base and having a plurality of projections extendingaway from said base, a relay coil mounted upon one of said projections,an armature associated with said coil, a pair of switch assembliesactuated by said armature, said assemblies being mounted uponprojections located on one side of the coil, one of said assembliescomprising av pair of spaced apart relatively xed contact arms and anintermediate movable contact arm actuatable by said armature fromengagement with one into engagement with the other of said fixed contactarms, and a third relatively iixed contact arm located adjacent theothers, and the second of said assemblies comprising a substantially U-shaped bimetallic contact arm, having a free leg actuatable by saidarmature into engagement with said third contact arm, said free legbeing surrounded by heating means.

13. A relay including, in combination, a coil,

an armature operable thereby, a contact carrying arm operable by saidarmature from one position to another, said arm being made of bimetallicmaterial, and means including a heating element in heat transferrelationship to said arm y energized simultaneously with said coil fortemporarily maintaining said arm in its said other position afterde-energization of said coil.

14. In apparatus of the class described, the combination including, anelectric motor having a eld winding, a relay having a. coil, an armatureoperable thereby, and switch means operable by said armature forcontrolling the circuit connections of said motor, said switch meansincluding a contact carrying arm operable from a.

iield circuit opening to field circuit closing posi-A operable into onand oil' positions wherein it is adapted to remain until again operated,means controlled by said switch for eiecting energization of said motorto operate the wiping means when said switch is operated to its onposition, means eiective upon operation of said switch to its -oifposition for maintaining energization ofA said motor until said wipingmeans reaches a predetermined position, and temperature compensatedmeans effective upon said wiping means Y Winding in circuit with saidcontrol'switch and energizable by said switch when the latter is in 4oneposition, means operable by said relay when said switch is operated intosaid one position for connecting the motor to the source of energy, acam actuated switch operable by the motor for maintaining said relayenergized when said control switch is operated to its other positionuntil the wiping means is in a predetermined position,

and means associated with the means operable by the relay forautomatically dynamically braking the motor for a time interval afterdeenergization of said relay.

1'?. In apparatus of the class described, the combination including, anelectric motor having a eld winding and an armature, a relay, switchmeans operable by said relay for controlling the circuit connections ofsaid motor, said switch means including a rst contact carrying armoperable from armature shorting position to armature energizing positionupon energization of said relay and from armature energizing to armatureshorting position upon deenergization of said relay, said switch meansincluding also a second contact carrying arm operable from a fieldcircuit opening to eld circuit closing position upon energization ofsaid relay, said second mentioned arm being made of bimetallic material,and means including a heating element in heat transfer relationship tosaid second mentioned arm energizable simultaneously with said coil fortemporarily maintaining said arm in field circuit closing position afterdeenergization of said relay.

` GEO. E. COXON.

WILLARD H. FARR.

